1. Field of the Invention
The present invention is related to a fan device, particularly to a fan device mounted on the cooling fins.
2. Brief Description of Related Art
Generally, a conventional fan as shown in FIG. 1 is basically composed of a frame 111 and a fan blade part 112. The fan blade part 112 is further composed of a fan hub 112a and fan blades surrounding the fan hub 112a. The frame 111 has a driving part 111a, which rotationally joins with the fan hub 112a, fixedly attached to the center of the frame 111 by means of locating posts 111b in a way of the engaging surface 111d of the driving part 111a being flush with a facial side 111c of the frame 111.
Referring to FIG. 2 in company with FIG. 1, during being assembled, the fan device is engaged to the radiator 13 by way of the screw thread components 12 passing through holes 111e of the frame and fastening to the cooling fins 131. Then, the fan, which is associated with the radiator, is mounted on the chip 141, which is attached to the circuit board 14.
Referring to FIG. 3, once the fan blade part 112 is actuated to rotate by the driving part 111a, it occurs a phenomenon that air current under the engaging surface 111d of the driving part 111a produces a large stagnation zone and it results in undesirable cooling effect.